(Northeastern University, Key Laboratory of Electromagnetic Processing of Materials, Shenyang 110004, China)
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DOI:
10.7502/j.issn.1674-3962.2012.04.03
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Abstract:
Half Heusler alloys have attracted much attention in recent years as a candidate material for room temperature magnetic refrigeration. They have a promising prospect for industrial applications due to low costs of raw materials. In terms of their chemical compositions, they can be classified into three groups: Co based, Ni based and Fe based alloys. Alloying is an important method for adjusting their phase transition temperatures and magnetic properties. By using substitutional atoms, interstitial alloys and nonstoichiometric compositions, the magnetic phase transition temperatures can be shifted to room temperature, and their differences from the structural transition temperatures can also be minimized, which are required for the generation of a first order magnetic transition and therefore a large magnetocaloric effect. It is expected that alloying will continue to be an important research topics in the future study of half Heusler alloys for room temperature magnetic refrigeration. Meanwhile, attention should be paid to the issues of brittleness and hysteresis occurring during phase transitions.